Research Of Cognitive Radio Network’s Routing Protocol And Its Application In The Smart Grid

Wireless spectrum is precious and non-renewable. With the development of the future wireless communication, new technology and new traffic will be constantly emerging. Then the demand of spectrum will increase exponentially. The scarcity of spectrum limits the development of wireless communication traffic’s application. Cognitive radio is a kind of spectrum sharing technology, which can recycle nonrenewable spectrum resources. In this way, it can effectively relieve the pressure caused by the lack of spectrum resources. Due to the lack of research of the cognitive radio’s routing protocol, this paper improves the AODV protocol to make it able to apply to the cognitive radio networks.Firstly, this paper analyzes a series of problems if AODV protocol applied to the cognitive radio Ad Hoc networks directly. The problems are mainly caused by the selection of frequencies. Then, this paper proposes the improved model and assumptions, using the ON/OFF stochastic process. This paper does a series of changes in the routing table, RREQ, RREP and Hello control group to make AODV protocol into CAODV protocol. It mainly increases the spectrum management. At last, we analyze the process of the routing.We use the AODV module existed in the MANET model of OPNET(Optimized Network Engineering Tool) library. With some necessary modules making up cognitive nodes, we build a cognitive wireless Ad Hoc network. Then we analyze the performance of the network and compare it with the network using AODV protocol.Paper finally analyzes smart grid’s communication status to find the place to use CR technology. CR technology is applied to the user side, that is, to realize the spectrum sharing of heterogeneous network. CR technology is applied to the distribution network, adopting the technology of WAN and using authorized frequencies. When the spectrum resources are insufficient, CR technology would be used to find the available resources. We use OPNET software to simulate user side network’s and distribution network’s traffic. Finding that the more the number of available frequencies in the simulation, the distribution network’s delay is smaller. Changing the size and message sending interval, to a certain extent, delay will radiate and network’s performance falls sharply. When the channel is crowded, using CR technology to change the communication frequency will reduce delay and make the performance of network better.